Semiconductor materials and radiation detection

While Si and Ge have become detection standards for X-ray and gamma-ray spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by one or more of their physical limitations; namely the need for ancillary cooling systems or bulky cryogenics, their modest stopping powers and radiation intolerance. Wide band-gap compounds offer the ability to operate in a range of chemical, thermal and radiation environments while still maintaining sub-keV spectral resolution at X-ray wavelengths. In addition, these materials encompass such a wide range of physical properties that it is technically feasible to engineer materials to specific applications. However, while compound materials are used routinely in the optical and infrared wave bands, their development at hard X- and gamma-ray wavelengths has been plagued by material and fabrication problems. In this paper an overview of suitable materials is presented and the current progress in producing X- and gamma-ray radiation detectors is reviewed.